I'm getting a humming sound from my left front wheel. I also noticed that the left front is a little lower than the right side. Any ideas?

I am getting the same thing on my right rear. Could be the calliper. I get it most of the times I brake - especially in wet.

My money is on wheel bearing. How many miles on the bearings?

Not sure how many miles on the bearings. Its been at least 40K; it could be much more. I'm also getting a crunch sound every once in a while when I turn the wheel.

I second the wheel bearing... jack the car up and check to see if there is any wheel play... good luck!